Hi, Rob! Fear not...several people will jump in on this. I'll take a first shot: open string buzz is usually at the first fret, which means NUT.
Fret all the strings at the first fret and see if the buzz goes away.
If it does, you may want to raise the nut a little. Loosen the center screw (which fastens it down) and then raise it with the two outside ones. The Alembic owner's manual page has info:
Good luck - EffClef.
http://www.alembic.com/support/care.html Brass Adjustable Nut
Our unique brass adjustable nut is featured on
every Alembic guitar and bass. There are three
adjustment screws on the string nut. The center
screw locks the nut in place and must be loosened
before attempting to raise or lower the nut. The
two outer screws determine the height of the nut.
The 5/64 hex driver supplied with your
instrument is required to make these adjustments.
Here's how to do it properly:
Detune the bass a little bit.
Loosen the center locking screw.
Adjust the outer screws to the desired height.
When you tighten one of the screws, the height
increases on that side only.
Tighten the center screw once the optimum height
is achieved.
You will need to change the string nut height
when you change the gauge of your strings.
Smaller gauge strings will rest lower in the nut
slots than larger ones. If you dramatically
change the strings, you may need to order a new
nut than can be slotted to your new string size.
You also need to raise the nut if you have a
persistent buzz on open strings.
The nut does not need to be adjusted equally on
both sides. You may want the nut to slant in
certain situations. For cleaning, see the brass
care section of this document.